KTTV's origins can be traced to December 1946, when the station's license and construction permit was secured by the Times-Mirror Company, publishers of the Los Angeles Times. It was one of five licenses that were granted simultaneously by the Federal Communications Commission (FCC) to parties interested in launching commercial television stations in Los Angeles. In 1948, CBS, which owned KNX radio, purchased a 49% interest in the station and assisted in completing its construction in exchange for making channel 11 the network's Los Angeles television outlet.[1] KTTV began operations on January 1, 1949 and was operated initially by KTTV, Incorporated, the Times/CBS-owned holding company. The station's first telecast was the Tournament of Roses Parade,[2] which channel 11 would air every New Year's Day until 1995.

In May 1950, Times-Mirror purchased the Nassour Studios – a large motion picture facility on Sunset Boulevard in Hollywood, and centralized KTTV's operations there.[3][4] CBS did not join Times-Mirror in the purchase; at the time its West Coast production facilities were based at Columbia Square, with its CBS Television City facility in the planning stages. KTTV converted the Nassour Studios into a major production house for television, producing programs locally and for the emerging syndication market. Prior to the move, KTTV operated out of several different facilities, including the former headquarters of Capitol Records (which was later the longtime home of KHJ radio and what is now KCAL-TV) on Melrose Avenue.[5]

Later in 1950, CBS chose to acquire its own station in Los Angeles – KTSL (channel 2, later KNXT and now KCBS-TV) – which was being spun off by the Don Lee Broadcasting System as a result of its sale to General Tire and Rubber. The KTSL purchase forced CBS to divest its interest in KTTV due to FCC rules in effect at the time that barred the common ownership of two television stations in the same media market; the Los Angeles Times would regain full ownership of channel 11 when the sales were finalized on January 1, 1951. KTTV's relationship with CBS ended after exactly two years as the network moved its programming to KTSL.[6][7] A few months later, channel 11 agreed to become the new Los Angeles outlet of the DuMont Television Network, which had been affiliated with KTSL and, before that, KTLA (channel 5).[8]

In 1954, DuMont moved its programming to KHJ-TV (channel 9, now KCAL-TV),[9] and KTTV became an independent station. During the late 1950s, the station was also briefly affiliated with the NTA Film Network.[10] In 1958, channel 11 scored an advantage against its rivals when it became the television home of the Los Angeles Dodgers baseball team, which had relocated from Brooklyn, New York that year.[11] For the first 11 years and at the request of the team, KTTV's Dodger telecasts were limited to road games against the archrival San Francisco Giants. Eventually, the number of Dodger games broadcast on the station increased and the home game blackout was lifted; the relationship between KTTV and the Dodgers would last until 1992.

The Times-Mirror Company sold the station to Metromedia in 1963.[12][13][14] Later that year, Metromedia purchased KLAC (570 AM) and the original KLAC-FM (102.7 FM, now KIIS-FM), giving channel 11 sister stations on the radio dial.[15] Metromedia would later engineer a trade of FM frequencies, resulting in KLAC-FM moving to 94.7 FM (later to become KMET, now KTWV) in 1965.[16]

By the 1970s, KTTV offered a traditional general entertainment schedule common among independent stations at the time, consisting of children's programs, off-network reruns, sports programming and movies, along with a 10:00 p.m. newscast. The station, along with KTLA, KCOP and KHJ-TV, became a regional superstation that was seen on various cable television providers across the southwestern United States during the 1970s and into the 1980s, as far east as El Paso, Texas.

In 1986, Australian newspaper publisher Rupert Murdoch and his company, the News Corporation (which had acquired a controlling ownership interest in the 20th Century Fox film studio the year before), purchased KTTV and the other Metromedia television stations. The Metromedia stations ended up becoming part of a new holding company formed by News Corporation called Fox Television Stations; those stations formed the basis for the new Fox Broadcasting Company television network, which made its debut on October 9, 1986. Following the News Corporation purchase, KTTV added more first-run syndicated talk, court and reality shows. By the early 1990s, it began to run afternoon cartoons from the network's Fox Kids block (which debuted in 1990), as well as top rated off-network sitcoms during the evening hours. KTTV removed cartoons on weekday mornings in June 1993, due to the launch of the morning newscast Good Day L.A.

In 2001, Fox Television Stations acquired several UPN affiliates owned by Chris-Craft Industries through its BHC Communications station group, effectively creating a duopoly between KTTV and KCOP-TV (channel 13). That fall, channel 11 dropped the Fox Kids weekday block and moved it to KCOP; Fox Kids discontinued its weekday block altogether in January 2002, with the lineup left now airing only on Saturday mornings under the new Fox Box branding (which was replaced by 4Kids TV in September 2002), KTTV began to air Fox's children's programming once again. Since the 4Kids block was replaced by Fox with the infomercial block Weekend Marketplace in December 2008, the station now airs five hours of educational programming, two more than required under FCC guidelines, as Xploration Station replaced Weekend Marketplace, which moved to KCOP, in September 2014.

KTTV also airs reruns of I Love Lucy, which had premiered in 1951, months after the station lost its CBS affiliation. Reruns of the sitcom are still popular among Southern California viewers and have continued to air in the Los Angeles market perpetually since the series ended its run in 1957, thus making KTTV only the second station in the market (the other being KCBS-TV) to continue airing the sitcom since it ended. Weekday airings of "I Love Lucy" have since moved to KCOP (which airs the program in a two-hour block), but KTTV continues to air the landmark sitcom on weekends during the late afternoon hours.

On May 16, 2006, KTTV launched a new website based on Fox Television Stations' MyFox interface; this format became standard on the websites of each of the Fox-owned stations – and was even adopted by some of Fox's affiliates not owned by the network – by the end of that year (the "MyFox" branded websites were operated by former News Corporation subsidiary EndPlay until 2012, when the sites were migrated to the WorldNow platform[17]).

KTTV shut down its analog signal, over VHF channel 11, on June 12, 2009, as part of the federally mandated transition from analog to digital television.[21][22] The station's digital signal relocated from its pre-transition UHF channel 65, which was among the high band UHF channels (52-69) that were removed from broadcasting use as a result of the transition, to its analog-era VHF channel 11 for post-transition operations.[23]

KTTV presently broadcasts 46 1/2 hours of local newscasts each week (with 8½ hours on weekdays and two hours each on Saturdays and Sundays); this gives KTTV the second-largest local news output of any television station in the Los Angeles market, behind CW affiliate KTLA's 69 1/2 hours of weekly newscasts. As is standard with Fox stations that carry early evening weekend newscasts, KTTV's Saturday and Sunday 5 p.m. newscasts are subject to delay or preemption due to network sports coverage. KTTV operates a Eurocopter A-Star 350 B-1, branded on-air as "SkyFox HD" (pictured right), to provide aerial coverage of breaking news stories. KTTV previously operated two helicopters; one of them (known as "Sky Fox 2") was destroyed after it crashed at Van Nuys Airport in 2000.

Throughout its history, the station has always operated a news department, partly owing to its former ties to the Los Angeles Times (which has been owned by the Tribune Company, owner of rival KTLA, since 2000). KTTV aired an 8 p.m. newscast from 1984 to 1986; it also briefly moved its 10 p.m. newscast to 11 p.m. in 1986, in order to compete with existing local newscasts in that same timeslot on KABC-TV, KNBC and KCBS-TV; the newscast's format initially was unchanged, but the 8 p.m. edition was later dropped while the 11 p.m. newscast reverted to its previous 10 p.m. slot shortly after News Corporation took over Metromedia in 1986.

In June 1993, the station launched a new morning news program called Good Day L.A., a program that was inspired by sister station WNYW's Good Day New York, which debuted in 1988. On July 14, 2008, KTTV launched a half-hour 10 a.m. newscast, following Good Day L.A., as the station's first midday newscast since the mid-1980s; KTTV is currently the only station in Los Angeles to have a local newscast in that timeslot. KTTV and KCOP began producing its local newscasts in high definition on October 15, 2008. On December 1, 2008, KTTV fully took over production of KCOP's 11 p.m. newscast, which was reduced from an hour to 30 minutes and retitled Fox News at 11, marking the end of a KCOP-produced and branded newscast. The newscast on channel 13 then became anchored by KTTV's 10 p.m. anchors Carlos Amezcua and Christine Devine, as it was considered an extension of the earlier newscast.

On December 8, 2008, KTTV debuted a half-hour midday newscast at noon on weekdays. On April 27, 2009, KTTV introduced Good Day L.A. Today, a recap program airing at 12:30 p.m. weekdays that featured select segments featured on that day's edition of Good Day L.A.;[24] that show has since been replaced by TMZ on TV. On April 12, 2010, the station expanded its weekday morning newscast by a half-hour to 4:30 a.m. Until September 12, 2011, KTTV was one of only two Fox owned-and-operated stations (the other being Chicago's WFLD) that did not have an early evening newscast on weeknights and/or weekends; this changed when KTTV launched an hour-long 5 p.m. newscast on that date called Studio 11 L.A.[25][26] On June 30, 2014 KTTV expanded its noon newscast from 30 minutes to 1 hour.

On July 26, 2007, KTTV aired a report on the hacktivist group Anonymous, calling them a group of "hackers on steroids", "domestic terrorists", and collectively an "Internet hate machine". The report, which became the source for numerous internet memes, featured an unnamed former "hacker" who had fallen out with Anonymous and explained his view of the Anonymous culture. In addition, the report also mentioned "raids" on Habbo, a "national campaign to spoil the new Harry Potter book ending", and threats to "bomb sports stadiums".[27]